Manufacture of steel rails for railroads



UNITED STATES PATENT OFFICE.

HAYWARD A. HARVEY, OF ORANGE, ASSIGN OR TO THE HARVEY STEEL COMPANY, OF NEWARK, NEW JERSEY.

MANUFACTURE OF STEEL RAILS FOR RAILROADS.

SPECIFICATION forming part of Letters Patent No. 506,689, dated October 17, 1893.

Application filed March 29, 1893. Serial No. 468,224. (No speoimens.)

,shall also possess such hardness of surface upon their heads as will prevent them from rapid wear in use. The desired result is secured by the production of a steel rail, the upper portion of the head of which contains five tenths of one per cent. or more of carbon, while the remainder of the head and the shank contains from two and a halt` tenths of one per cent, to four tenths of one per cent. of carbon, and the flange contains less than two tenths of one per cent. of carbon. The economical production of such a rail is effected by rolling it from a bloom which has been suitably supercarburized upon the side which is ultimately intended to form the head of the rail, and has been suitably decarburized upon the side which is intended to ultimately form the flange of the rail. The bloom is made in the ordinary Way from steel preferably containing not less than three tenths of one per cent. of carbon, and not more than four tenths of one percent. of carbon. The prescribed supercarburization and decarburization of the bloom may be effected bysu bj ecting the bloom to intense heat Whileembedded in .a mass of granular materials arranged in three superposed strata, and deposited in a suitable treating chamber contained within the heating chamber of a furnace. The side of the bloom which is to be decarburized is covered and inclosed to the distance, say, of one inch more or less in a granular stratum composed of sand and fine iron ore. The side of the bloom which is to be supercarburized is embedded tothe depth of an inch, more or less, in a stratum of granular carbonaceous material which is firmly compressed against the bloom, while the middle portion of the bloom is surrounded by a stratum of fine clay which intervenes between the stratum of carbonaceous material and the stratum of mixed and iron ore. This mode of treating the bloom been embedded and is rolled into a rail in the mass of granular materials in which it has ordinary way with the result that the superoarburized portion is elongated and spread thinly over the surface ot' the head of the rail, while the decarburized portion is formed into the flange of the rail. The percentage l of carbon present in the upper portion of the head of the rail produced in the manner herein described, will be greatest at the surface and will gradually diminish from the surface inward. By so conducting the process as to make the added portion of carbon large, the' stratum of metal upon the top of the head, that is, the part ofthe rail commonly called the tread, will by the mere act of rolling and finishing the rail be made to acquire a condition of excessive hardness. The remainder of the head and the shank Will be only moderately hard, While the flange Will be quite soft. It will be seen that considerable range is permissible in` the percentage of carbon which may be employed. in that portion ot' the metal forming the tread of the rail, and similarly, that a wide range is permissible in the percentage of carbon which may be employed in the main portion of the head and in the shank, and also that a considerable range is permissible in the quantity of carbon which may be employed in the liange of the rail, without in either case departing from the invention, the invention being present in a rail having an excessively hard tread, with the main portion of the head and the shank moderately hard and having a soft flange. l

The accompanying drawings illustrating the invention are as follows:

Figure l is a cross section of a furnace chamber and the receptacle containing the granular materials in which the billet is embedded for treatment, as herein described. Fig. 2 is a cross section of the billet after treatment, in which the different percentages of carbon in different parts of the biilet are symbolically indicated by differently spaced section lines. Fig. 3 is a cross section of a flanged T rail containing the invention in which the different percentages of carbon present in dierent parts of the rail are also symbolically indicated by dierently spaced section lines.

In carrying out the invention a homogeneous bloom is first made in the ordinary way out of steel containing preferably not less than two and one half tenths of one per cent. of carbon and preferably not more than four tenths of one per cent. of carbon; the object being to have a sufficient quantity of carbon to make the metal which is to ultimately constitute the shank and main portion of the head of the rail moderately hard without having so much carbon in it as to be ceous material is placed at the bottom of the` treating chamber, so that the weight of the bloom resting directly upon the carbonaceous material will insure a close contact under compression of the granular carbona ceous material with the side, f, of the bloom which is to be supercarburiz'ed. The stratum of granular material immediately above the carbonaceous bed may be composed of clay orv of any other substance which will nothave any material effect in decarburizing the metal of the bloom with which it is in contact. The upper stratum, E, of granular material is composed of sand or of a mixture of sand and tine iron ore, by means of which tne upper side, f', of the bloom will be partially decarburized during the subsequent heating process. The bloom having been thus embedded in the strata of granular material contained in the treating chamber is subjected to intense heat for such length of time as may be required in order to supercarburize the lower side of it to the depth of three quarters of an inch, more or less, and toy decarburize the upper side of it to a simi'- lar depth.

There are a great Variety of existing furnaces in which the process can be conducted. Such furnaces, of course, vary in their efliciency, but a few trials by an operator skilled in the use of any particular form of furnace and in the use of any particular kind of fuel will sufice for the determination of the time required for successfully producing the desired results in such form of furnace and with such fuel. The bloom having been treated for the desired length of time is then removed from the treating chamber and subjected to the action of successive roll passes by which it is transformed into a rail, as for example, the rail, G, having the form in cross section represented in Fig. 3. The bloom is so presented to the Various roll passes that the metal in the supercarburized side, f, is ultimately distributed upon the surface of the head, g, of the rail, while the metal of the decarburized portion, f', is so distributed as to form the lower portion of the flange g of the rail. The web, g2, of the rail is formed from the portion of the bloom which has not been materially affected by the treating process and hence the same or nearlyv ther same percentage of carbon as that originally present in the entire bloom.

What is claimed as the invention isl. The new article of manufacture herein described, the same consisting of a rolled steel rail for railways, the upper portion of the head of which rail' contains tive tenths of one per cent. or m-ore of carbon, while the remainder of the head and web contains not more than four tenths of one per cent. of carbon, and the lower portion of the ange not more than two tenths of one per cent. of carbon. f

2. As a new article of manufacture a rolled comparatively soft by reason of the relatively. small percentage of carbon present in the metal composing the tiange.

HAYWARD A. HARVEY. Witnesses:

FANNY S. HALsEY, GEO. P. KINGsLEY.

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